VulnerabilityPublished 18 Oct 2026

CVE-2026-98617: Linux kernel · eth: fbnic: use the Rx queue napi pointer to find the napi vector

Affects Linux kernelSource CVE Database V5

Not known to be exploited : upgrade to b5d9e9d4d0c13bc8b60d8d97e7a07fb25fea639e or 1fb569cf3bf97e552f465b2c719e36b48ae7c18b when convenient.

Data as of 26 Oct 2026, 12:55 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in b5d9e9d4d0c13bc8b60d8d97e7a07fb25fea639e, 1fb569cf3bf97e552f465b2c719e36b48ae7c18b

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to b5d9e9d4d0c13bc8b60d8d97e7a07fb25fea639e or 1fb569cf3bf97e552f465b2c719e36b48ae7c18b.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ da43127a8edc7498cce7b2554533f4027c618933, < b5d9e9d4d0c13bc8b60d8d97e7a07fb25fea639e	Fixed in b5d9e9d4d0c13bc8b60d8d97e7a07fb25fea639e
LinuxLinux	Affected ≥ da43127a8edc7498cce7b2554533f4027c618933, < 1fb569cf3bf97e552f465b2c719e36b48ae7c18b	Fixed in 1fb569cf3bf97e552f465b2c719e36b48ae7c18b
LinuxLinux	Affected =6.18	Fixed in–
Debiandebian/linux`pkg:deb/debian/linux`Other threats	Affected =6.18	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in the Linux kernel as indicated by the fixed commit versions. Users should update to the fixed kernel versions to resolve this issue. No additional mitigation actions are required beyond applying the official fix.

Description

A vulnerability in the Linux kernel's fbnic network driver involves incorrect use of the Rx queue NAPI pointer to find the NAPI vector. The issue arises when standalone Tx vectors are present, causing the Rx queues to incorrectly point to Tx NAPI vectors. This can lead to improper queue management and potential instability. The flaw has been fixed by using the correct stored napi pointer in netdev_rx_queue.napi, ensuring proper queue handling under the netdev instance lock.

Impact

This vulnerability could cause the fbnic driver to reference incorrect NAPI vectors for Rx queues, potentially leading to queue mismanagement, instability, or crashes in the network data path. The issue affects the Linux kernel's network driver behavior but no known exploits in the wild have been reported.

Summary

The Linux kernel fbnic driver had a flaw in how it selected the NAPI vector for Rx queues. Previously, the code used an index-based modulo operation on the NAPI array, which was only correct when no standalone Tx vectors existed. When Tx vectors were allocated first, Rx queues incorrectly pointed to Tx NAPI vectors. The fix uses the napi pointer stored in netdev_rx_queue.napi, which is managed under the netdev instance lock, eliminating the incorrect indexing and preventing access to freed or invalid pointers during queue restarts or PCIe recovery scenarios.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 10:08 UTC

Technical details

References

Community reviews

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